Pestalotiopsis linguae Li Hua, Manawas., & YX Zhang. 2023, sp. nov.

Pestalotiopsis linguae Li Hua, Manawas., & YX Zhang. sp. nov. (FIGURE 3).

Index Fungourum number: IF 559839;

Facesoffungi number: FOF 12712.

Etymology: Epithet refers to the host species from which the fungus was isolated

Holotype: ZHKU 22-0089

Endophytic on the Pyrrosia lingua (Polypodiaceae) leaves. Sexual morph: not observed. Asexual morph: Conidiomata acervular, 800–1,100 μm diameter, globose, solitary or aggregated in clusters, exuding black conidial masses. Conidiophores reduced to conidiogenous cells. Conidiogenous cells discrete or integrated, cylindrical to subcylindrical, hyaline, smooth, annelidic. Conidia (16.5–)18–21(–23) × (4–)5–7(–8) μm (x̅±SD=19.2±1.4 × 5.9±0.8 μm, n=30), fusoid, ellipsoid, straight or slightly curved, 4-septate; basal cell conical, (2–)3–5 μm, hyaline, smooth, thin-walled; with a single appendage (3–)4–7(–8) μm (x̅±SD=5±1.3 μm, n=30) long, filiform, unbranched, centric; three median cellsdoliiform, (11–)11.5–13(–14) μm (x̅±SD=12.2±0.7 μm, n=30) long, smooth, concolorous, brown, septa darker than the restof the cell (second cell from base (3–)4–5 μm long; third cell (2–)3–4(–5) μm long; fourth cell (3–)4–5 μm long); apical cell conical, (2.5–)3–4(–4.5) μm (x̅±SD=3.7±0.5 μm, n=30) long, hyaline, smooth, thin-walled; with 2–3 apicaltubular appendages (10–)12–17(–21.5) μm (x̅±SD=14.9±2.5 μm, n=30) long, unbranched, filiform.

Culture characteristics: Colonies on PDA reaching 50 mm diameter after five days at 25 ℃. Colonies filamentous to circular, medium dense, white aerial mycelium on surface flat or raised.

Material examined: CHINA, Guangdong Province, Guangzhou City, from the leaf of Pyrrosia lingua (Thunb.) Farwell (23°11’13”N 113°17’51”E), 16 August. 2021, Li Hua (holotype ZHKU 22-0089 as dry culture); ex-type living culture ZHKUCC 22-0159, ibid ZHKUCC 22-0160.

Notes: Two isolates in this study developed a clustered with 78% ML and 1.00 BYPP values. In the phylogenetic tree, our isolates show a particular neighbouring to seven known Pestalotipsis species, but they differ in morphology. The length of the base appendage of P. linguae is longer than that of P. formosana (4–7 μm vs. 3–5 μm), P. kandelicola (4–7 μm vs. 2.5–3 μm), P. parva (4–7 μm vs. 2–4 μm), and P. etonensis (4–7 μm vs. 2–4.5 μm). The length of conidia of P. linguae is shorter than that of P. kandelicola (18–21 μm vs. 20–23.5 μm), P. nanningensis (18–21 μm vs. 24–26.5 μm), P. thailandica (18–21 μm vs. 21–25 μm), P. rhizophorae (18–21 μm vs. 20.5–27 μm), but its conidia is longer than P. etonensis (18–21 μm vs. 15–21 μm). The apical appendage of P. linguae is longer than that of P. nanningensis (12–17 μm). vs. 18–22.5 μm) shorter and longer than P. parva (12–17 μm vs. 6.5–12 μm). In addition, P. lingua can also differ by P. formosana based on the base pair differences (2/ 523 in ITS, 3/ 452 in tef 1-α and 3/ 692 in tub2, no gaps). A strict morphological comparison of our isolates and their phylogenetically related species is presented in TABLE 2. Furthermore, the PHI analysis showed no evidence of genetic recombination between P. linguae and P. formosana, P. nanningensis, P. parva, or P. kandelicola. Therefore, the collection in this study is designated as a new species.